I’m Sick! I Read It on the Web!

A little knowledge is a dangerous thing.

So said the 18th century’s Alexander Pope in “An Essay on Criticism.” So said, in so many words, the 19th century’s T.H. Huxley in “On Elementary Instruction Physiology.” So said the 20th century’s Albert Einstein, who added a second sentence, “So is a lot.”

Each of these people turned up in a Google search as the author of that expression. If you Googled “dangerous knowledge” in the hope of finding out who who said it first, chances are excellent you would get a misguided result. You can find knowledge on the ‘net, but finding context and fact is a bit more daunting.

experimental treatments or medicines (15 percent, up from 10 percent).

We’re big fans of medical consumers informing themselves about health topics and quality of care. But context and and factual information aren’t always found where Googlers are looking.

A recent study published in Psychological Science shed some light on the common consumer habit of matching one’s symptoms with disorders described on the Internet to make wholly misguided self-diagnoses. Got a headache, nausea and fatigue? Websites listing these symptoms prompt far too many people to conclude erroneously that they have brain cancer.

As explained in a story on The Daily Beast, the response is a Web-enabled hypochondria called “cyberchondria,” and it can be as complicating as it is helpful.

The Psychological Science researchers said the brains of cyberchondriacs are like those of gamblers. It’s about pattern recognition, and what can go wrong when the brain tries to impose order on chaos. Cyberchondriacs who see patterns in lists of symptoms make the same mistake as gamblers who see patterns in random events such as consecutive rolls of the dice. The latter might conclude, erroneously, that a positive result on one or two rolls will repeat. The former might conclude that experiencing some symptoms in a list of several means they must have all of the other symptoms as well.

The researchers made up a type of thyroid cancer for which they also made up six symptoms. They composed three differently ordered lists of the same six symptoms. One grouped the milder, more common symptoms (fatigue, shortness of breath) at the top, and the more severe and rarer symptoms (pain in the throat or neck, lump in the throat or neck) at the bottom. One list ordered the more severe symptoms first, followed by the milder ones. The third mixed all the symptoms.

Different groups of healthy subjects were shown one of the lists, told to check off their symptoms, then asked how likely they were to have that cancer relative to the average American. Both groups with the lists of mild symptoms separated from severe symptoms were far more likely to believe themselves at risk for this fake problem than the group with the randomly listed symptoms.

The gift of pattern recognition can undermine the basic logic of probability. Gamblers say they have a “hot hand”; cyberchondriacs believe they have “hot symptoms”—if they hit the first two in a list, they believe they must have the third one as well.

Knock yourself out with medical research, but refrain from self-diagnosing until you consult with a medical professional. You might have a brain tumor, but it’s far more likely that your eyeglass prescription has changed, your milk has gone a bit sour and you’re not getting enough sleep.